按泵的工作压力分类中压泵消防车泵的额定工作压力大于等于（）MPa，小于（）Mpa。

阅读理解。

     Hi! I'm Harry. Life used to be kind of difficult for me. The muscles (肌肉) in my arms and legs are weak.

I have to be in a wheelchair all day. I can't use my legs at all, and I'm not too great with my hands. If I drop

something it stays dropped until someone picks it up for me. I can't open doors or switch lights on and off.

Carrying everything I need for school is a problem too.

    Now things are easier. I have a helping hand. Pete is a golden dog that has been trained to help kids like me.

Pete was at dog training school for two years to learn how to do different tasks. I had to be trained too. I had

to learn how to give Pete instructions and how to take care of him. 

    When Pete is working he doesn't play around. My friends know they are not to pet him or call him when

he is working. He can pull my wheelchair and pick up things I drop. Pete carries my books and lunch on his

back. He pushes the button on the school lift and opens some kinds of doors. He even knows how to switch

lights on.

    But best of all, Pete is here when I need a friend.

1. According to the passage, who is Harry's helping hand?

A. Pete

B. His teacher

C. His brother

D. His parent

2. Why is Harry kept in a wheelchair all day?

A. Because his legs are broken.

B. Because his leg muscles are weak.

C. Because he is too lazy.

D. Because he likes it.

3. According to the passage, which of the following about Pete is not true?

A. Pete can clean Harry's room.

B. Pete can switch lights on.

C. Pete can pull Harry's wheelchair.

D. Pete can push the button on the school lift.

4. What does the writer mean by saying "Pete is here when I need a friend."?

A. Pete is only a helpful tool for him.

B. Pete is with him all the time.

C. Pete is a funny dog to make him happy.

D. Pete is not only a helping hand but also his good friend.

马克思主义哲学的创立是哲学史上的伟大变革，使哲学获得了真正科学的性质，成为科学的世界观和方法论。马克思主义哲学以前的唯物主义的主要缺陷是[ ]

①具有形而上学性

②不承认社会存在决定社会意识

③不承认存在决定思维

④对社会历史的观点是唯心主义的

A、①②③

B、①②④

C、①③④

D、②③④

企业经营环境分类中的变化程度和复杂程度，包括( )。

A．不确定性

B．简单

C．复杂

D．稳态

E．动态

为引进外资发展经济，我国许多地方都提供了非常优惠的条件。不过，外资企业在并购中国企业时要求绝对控股，拒绝接受不良资产，要求拥有并限制原有中国品牌。例如，我国最大的工程机械制造企业被美国某投资集团收购了85%的股权；德国公司收购了我国一家油嘴油泵的龙头企业，我国首家上市的某轴承股份有限公司在与德国一家公司合资两年后，成了德方的独家公司。 以下哪项可以最合乎逻辑地完成上面的论述( )。

A．以优惠条件引进外资有可能危害中国的产业

B．以优惠条件引进外资是为了引进先进的技术和管理

C．在市场经济条件下资本和股权是流动的

D．以优惠条件引进外资是由于我国现在缺少资金

请说出现行原奶掺假实验原理。